I performed an update to the GM candidate using the App Store (redeemed the code from the Apple Beta page).
I had some trouble getting the installer to display in Clover, so I updated Clover to the latest version. Once that was fixed, I had some issues getting the installer's GUI/progress bar to load. Fixed by rebooting and applying nv_disable=1 to my boot options in Clover.
Install went off without a hitch from there.
After reboot/install, audio and my Nvidia drivers were non-functional. I installed the AppleHDA1150 driver that I'd used reliably for so long, as well as the latest Nvidia driver for Sierra. Upon reboot, I had no audio, nor any Nvidia drivers.
After searching a long while, here are the solutions that worked for me:
Audio:
Installed
VoodooHDA. After installing, I copied /System/Library/Extensions/VoodooHDA.kext to my desktop, right-clicked to Show Package Contents, and edited the info.plist file in the Contents folder. I set the iGain value to 0, and the PCM value to 100, then saved and used Kext Wizard to complete the install. Basically, this final step of editing the kext resulted in me NOT having an extremely loud hum coming from my speakers each time I would perform a reboot, necessitating me messing around with the VoodooHDA settings.
Video:
The new Nvidia web driver or Sierra apparently doesn't accept nvda_drv=1 in the boot flags in Clover, so the below steps were necessary (copied from forum user ueer3fc). Areas in bold, below, should be entered into a terminal, such as iTerm2 or the Mac's built-in terminal application:
1. Added nvda_drv=1 to my nvram:
sudo nvram nvda_drv=1
2. Exported the nvram to a plist file:
nvram -x -p >nvram.plist
3. Moved nvram.plist to the root:
sudo mv ./nvram.plist /nvram.plist
4. To be sure, I made it accessible for all (this might be superfluous):
sudo chmod 777 /nvram.plist
5. Made nvram.plist hidden for Finder (for aesthetic reasons):
chflags hidden /nvram.plist
6. Enabled EmuVariableUefi-64.efi using Clover Configurator
7. Rebooted
Everything on my system is 100% functional now - it was nearly unusable without the Nvidia drivers being loaded. I did something stupid to corrupt my ~/Library/Preferences folder (one of the 308 items in there), but aside from that, the
system didn't do anything weird after the upgrade.
I'm extremely happy and grateful for this forum and its members for sharing their knowledge. I hope this post is able to help someone else who is running into the same problems that I ran into through this upgrade process. I did not install any of the betas on my hackintosh before installing the GM.